Progress and Challenges in Foundational Hypersonics Research
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Transcript of Progress and Challenges in Foundational Hypersonics Research
Progress and Challenges in Foundational Hypersonics Research
April 2011
John D. SchmisseurProgram Manager
AFOSR/NA
Air Force Office of Scientific Research
AFOSR
Thanks:Mike Wright, Jim Pittman, and Deepak Bose - NASA
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High-Temperature,Light, Durable
Materials
Optimized Aerodynamicsand Flow Control
Enhanced Ignitionand Combustion
Innovative Flowpaths
Advanced Sensors andCommunications
Advanced Flight Controls,Closed-Loop Optimization Control
Hypersonic Flight:Challenging Science & Integration
Development of Hypersonic Capabilities Requires the
Integration of Contributions from a variety of Disciplines
Thermal Management
Advanced Numerical Simulations and Diagnostics
Hypersonic: High-speed flow regime where energy transfer between the flow and thermodynamic and chemical processes becomes significant
Image Courtesy Kei Lau, Boeing
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Foundational Research:“Building Blocks of a Technology Base”
Goals of Basic/Foundational Science – requires balanced investment• Foster scientific innovation to radically change the status quo
– the “basic” part• Develop and utilize essential science to overcome technology show-
stoppers – the “foundational” part
National Aeronautics R&D Plan
~ $20 MIn current FY
AFOSR – Basic• Aerothermo. & Turbulence• Combustion & Diagnostics• High-Temp. Materials• 3 Science Centers• 1 MURI
Fundamental Aero Hyp• Tools and
Technologies• Airbreathing Space Access
• High-Mass Planetary Entry• 3 Science Centers
• Academic research addresses aerothermo. & high-temp materials
• 2 PSAAP Centers with Hypersonic Topics
• Focus is on Advanced Numerics
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Outline
• Major collaborations and plans
• Challenges and opportunities
• Recent accomplishments
• Emerging game-changers
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A Coherent National Scientific Vision and Coordinated Research Investments
volatile history = eroding skill base
Pro
gra
m R
eso
urc
es1963 1978 1993
ASSET, PRIME
Shuttle X-43
Inspired by AF SAB-TR-00-03
2008
Foundational Research Base
Peo
ple
Unknown Program
Directions
???
Stable Base of Expertise
The National Hypersonic Foundational Research Plan• Provide a consistent science and technology base• Ensure the long-term availability of an expert knowledge base• Prepare for planned future hypersonic capabilities• Adopted by the JTOH as the basic research roadmap
Boundary Layer
Physics
Nonequilibrium Flows
Shock-Dominated
Flows
Supersonic Combustion
Objective: Advance Science to Address Critical Phenomena in 6 Thrust Areas
High-Temperature Materials & Structures
Environment-Structures &
Material Interactions
Near Term (2010)Semi-Empirical (Calibrated) Methods for 3-D Flows on Idealized Surfaces
AFRL HIFiRE 1- March 2010Axisymmetric
NASA HyBoLT – 2008-Flat with crossflow on sides – lost during launch
AFRL HIFiRE 5 – 3-D Geometry with significant crossflow
Continuous transition to tech maturation
Prompt Global Strike
Increasing 3-D Complexity
Responsive Space Access
Mid Term (2020)Extend Semi-Empirical Methods to Account for Realistic Surface Conditions
Far Term (2030)Physics-Based (Uncalibrated) Estimation for Actual Systems
NHFRP Goals: Boundary Layer Physics
Experiment
Simulation – artificially tripped
HYTHIRM: Near IR Image of Shuttle Orbiter ~ Mach 9
Orbiter experiments facilitate characterization of real surface effects
Planetary Entry
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U. Texas - Predictive Engineering and Computational Sciences (PECOS) Atmospheric Reentry
Stanford University: The Center for Predictive Simulations of Multi-Physics Flow Phenomena with Application to Integrated Hypersonic Systems
NSSEFF: Candler Thermophysics
CUIP Reentry Aerothermo-dynamics Portfolio
MURI: Fundamental Processes in High-Temperature Gas-Surface Interactions
AFRL/RB Computational Hypersonics Center at U. Michigan
AFRL/RB Midwest Structural Sciences Center at U. Illinois
HIFiREASRP: Scramjet-Based Access to Space – UQ consortium
Hypersonic Academic Research Partnership (HARP)
NHSC: Center for Hypersonic Combined Cycle Flow Physics, UVa
NHSC: Hypersonic Laminar-Turbulent Transition, Texas A&M
Basic Science(AFOSR/NASA)
Network of Academic Hypersonic Research Centers
Uncertainty Quantification & Verification and Validation (NNSA)
Application-Oriented (NASA ESMD)
Multidisciplinary Science and Transitioning 6.1
Research Objectives
Sci
entif
ic D
isci
plin
es
NHSC: Hypersonic Materials and Structures, Teledyne Scientific and Imaging
Joint AFOSR-NASA Fundamental Aeronautics Sponsored National Hypersonic Science Centers Extend Collaboration Initiated Under the Foundational Research PlanTotal of $30M in invested over 5 years
Coordinating over $20M in Annual Investment Across DoD, NASA, DoE/NNSA and ASRP
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Collaboration via NATO Research and Technology Organisation
A Rich History of International Collaboration in Hypersonics• WG 18: Hypersonic Experimental and Computational Capability,
Improvement and Validation (1991-1997)
• WG 10: Technologies for Propelled Hypersonic Flight (1998-2002)• AVT 136: Assessment of Aerothermodynamic Flight Prediction Tools
through Ground and Flight Experimentation (2005-2009)• Research community responds to opportunity to report
RTO contributions in international forum• Excerpts from Final Report to appear in
Journal of Progress in Aerospace Sciences
New Opportunities to participate in RTO Collaborations• AVT 205: Assessment of Predictive Capabilities for
Aerothermodynamic Heating of Hypersonic Systems (2012- )
• Led by Doyle Knight (Rutgers U.) and Olivier Chazot (VKI)
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Challenges
Micro-scale phenomena significantly impact macro-scale properties, i.e. the small stuff matters• Rate-dependent processes• “race” of instability growth for laminar-
turbulent transition• excitation/relaxation of internal energy states• material response in extreme environments
Access to the Hypersonic Environment remains exceptionally difficult• No ground test facility duplicates every aspect of flight• a few come close… • Flight Research seems to be a lost art• a few programs seek to provide scientific flight data
Technology priorities have shifted• The Cold War was driven by aerospace• Current interests: cyber-tech, socio-cultural, efficiency
hn
RotationalVibrational Electronic Reactions
Glass-Forming Ablator in ShearCourtesy Mike Wright, NASA Ames
Simulation from H. Fasel, U. Az.
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Opportunities
Unprecedented Insight Into Critical Phenomena• driven by large-scale computing and optical diagnostics
There is No Mature Industry Base for Hypersonic Systems• opportunity to rapidly transition science breakthroughs for integration into emerging systems!
DNS of SBLIP. Martin, U. Maryland
M=3 Nozzle With Hemisphere Body
Fletcher and Chazot, VKI
Spectroscopic Measurement of Transient Material Response
W. Rich, W. Lempert, and I. Adamovich Ohio State
Point measurement of vibrational and rotational/translational temperatures in less than 200 psec sampling time
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Coming Soon?: Flying the Mission – In Silica
81 million element, shock-tailored grid
Experiment
Simulation – artificially tripped
HYTHIRM: Near IR Image of Shuttle Orbiter ~ Mach 9
Surface Heat Flux and Instantaneous Flow Structure on an Elliptic Cone- 32M elements
Large-Scale Numerical Simulations Provide Unprecedented Insight Into Detailed Flow Physics• Massively parallel processing has dramatically
shortened run time – possible to “fly” mission• 230M element solution in 12-24 hours on 288 nodes• 0.5B element solution in ~12 hours on 4k nodes
Simulations Courtesy G. Candler, U. Minnesota
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HIFiREHypersonic International Flight Research Experimentation
$56M AFRL/Australian DSTO Collaborative Effort for Flight Research Exploring Critical Fundamental Phenomena
9 Flights Exploring Critical Science
International Partnership Provides Opportunity for Scientific Flight Research
Integrating All Resources
Experiment Computation
Flight Research
HIFiRE-0May 2009
HIFiRE-1Mar 2010
Risk reduction
Demonstrated flight software
BLT
SBLI
TDLAS
HIFiRE-5
3D BLT
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HIFiRE Flight 1 provides unprecedented insight into unsteady phenomenaR. Kimmel and D. Adamczak, AFRL/RB
Tunnel Expt - Dolling and Murphy
Note: Dissimilar Scales
Preliminary Results: Both transition and SBLI data reveal intermittent signals. Believed to be first such flight measurements for both phenomena.
International Partnership Provides Opportunity for Scientific Flight Research
Wind Tunnel Schlieren
Shock/Boundary Layer InteractionLaminar-Turbulent Transition
Co-ax TC< 10 Hz
Vatell HT1 kHz
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Aeroheating Uncertainty Assessment
Four Mission Relevant Problems
1. Compression Corner Turbulent Flow Mach 7 and14
2. Impinging Shock Turbulent Flow Mach 7 and14
3. High Mass Mars Entry Turbulent Flow Speed: 7 km/s
4. High Speed Return To Earth Turbulent Flow Speed: 15-16 km/s
Uncertainty assessed by a Panel of NASA Subject Matter Experts
Details will be presented at the 42nd AIAA Thermophysics Conference, Jun 27-30, Honolulu, HI
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Exploring the Effect of Roughness on Laminar-Turbulent Transition
• Measurements in thick laminar wall boundary layer allow increased spatial resolution, Mach 6 freestream
Joint Experimental-Computational Effort Yields First Detection of Roughness-Induced Instability at High Mach NumbersB. Wheaton and S. Schneider / Purdue U. - NASA/OSR
M.Bartkowicz and G. Candler / U. Minn - OSR/NSSEFF
DNS of Cylinder in Tunnel Wall Boundary Layer- Uses new low-dissipation numerical scheme
• 21 kHz signal first seen in experiments
• Computations reproduced instability and identified source
• Later experiments verified presence of instabilities predicted by computations at source
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Supersonic flow impacts the upper edge of the roughness
Temperature contour on centerline
Exploring the Effect of Roughness on Laminar-Turbulent Transition
Numerical Schlieren image on centerline
Numerical Simulations Identify Source of Roughness-Induced InstabilityM.Bartkowicz and G. Candler / U. MinnB. Wheaton and S. Schneider / Purdue U.
Experiment confirmed prediction of 21 kHz disturbance upstream of roughness element
Unsteady jet forms, creating unsteadiness in upstream vortex structure
Pressure gradient causes fluid to accelerate away from the high pressure region
Disturbances created upstream then travel downstream and grow
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Creating New Testing Capabilities
Recent-Developed Basic Research Methods Rapidly Transitioned to Revolutionize Ground Test of Major National ProgramsJ. Lafferty/ AEDC, G. Candler/ U. Minn. and S. Schneider / Purdue
Integrated Computations and Experiments provide unprecedented insight into sources and impact of critical aerothermodynamic phenomena
U. Minn. AEDC
Falcon HTV-2
High-Fidelity Numerical Methods yield detailed insight into physics
Innovative fluctuation measurements - Purdue
Temperature-Sensitive Paint provides global heating
AEDC Tunnel 9
Primary Test
Article
Low-Frequency Acoustic Pitot Probe
High-Frequency Acoustic Pitot Probe
Purdue /Sandia Transition Cone
Hemisphere Heat-Transfer Probe
Temperature Sensitive
Paint
Auxiliary Model
SupportFocused schlieren image of BL transition obtained on 7° transition cone at Mach 10, Re/L = 2.0×106/ft
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High-fidelity Ablator Modeling
• Fundamental studies: Monte-Carlo simulation of the ablation at the fiber scale
• High-fidelity ablator model formulated at the macroscopic scale
• Implementation in PATO-modular 3D CFD toolbox
• state-of-the-art already reached and passed; high-fidelity model 50% implemented
Next steps•First release of PATO: October 2011•Second release of PATO with UQ module:
October 2012•Coupling to hypersonics CFD tools: Oct. 2013•Full release of the high-fidelity PATO suite in
Oct. 2014.
Monte-Carlo simulation : Oxidation of the char layer of a low density carbon/phenolic composite (Stardust’s peak heating conditions)
PATO simulation : Ablation of a PICA cylinder, 1MW/m², 30 seconds, NASA Ames X-Jet (off-centered)
High-Fidelity Ablator Modeling
Multi-scale, Multidisciplinary Modeling Advances Ablator Simulations
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Advanced Ablators
Technical Considerations• Utilize flexible fibrous substrate systems• Modify polymer resin systems for increased
flexibility• Incorporate endothermic additives and
radiation inhibitors• Utilize multi-scale modeling to inform
processing and design approaches for advanced TPS
•Utilize commercially available constituent materials
• Incorporation of additives for tailored properties
•Extensive arcjet testing required for TPS maturation
6-inch radius6-inch radius
3-inch radius3-inch radius
Conventional Configurations
NASA Program Advances Mission-Tailored Ablator Families
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MURI: Fundamental Processes in High-Temperature Hypersonic Flows
University of Minnesota, Penn State University, Montana State University, University of Arizona, and University of Buffalo
Approach
Graham V. Candler, Don Truhlar, Adri van Duin, Tim Minton, Deborah LevinTom Schwartzentruber, Erica Corral, Dan Kelley and Paul DesJardin
•Use detailed quantum mechanics to develop accurate force fields for key processes
•Train reactive force field for MD simulations of post-shock wave flows and gas-surface interactions
•Extend to continuum models with DSMC models and state-specific simulations
•Perform experiments at all scales to provide validation data for model generation
Molecular Dynamics
High-Fidelity, Large-Scale CFD
MURI Explores Molecular scale Kinetic Processes to Advance Simulation of Vehicle Scale PhenomenaIntegration of Aerothermodynamics, Chemistry and Materials Research to develop advanced models for gas-surface interactions
Reaction Dynamics Experiments
Reactive Force Fields
Material Surface Effects
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Rethinking the Approach to Turbulence
Spark-Ignited Methane-Air
Orion Nebula
Non-Kolmogorov Turbulence: “Injecting energy into critical scales of the reactive-flowsystem must alter the system’s behavior ...”E. Oran, Naval Research Laboratory
Randomly Forced Broadband Turbulence•Energy spectrum can have a number of envelopes, including k-5/3 typical of Kolmogorov spectra
•Higher moments, such as vorticity or enstropy can behave differently
• Intermittancy is suppressed
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InstabilityAcoustic Absorption
diffusive transport of chemical energy
transport ofthermal energy
Surface Heat Transfer Equation
Changing the Technology ParadigmAn Opportunity for Transformation
Control the gradient via boundary layer management
Improve models for energy transfer
How can we actively control energy transport to optimize system performance?
Control T via energy management
Reliable models for Gas-Surface Interactions
23
Exploring Transition Control Via Energy Transfer to Internal Modes
Transition Delay Resulting from CO2 Injection in Boundary Layer Provides Potential Mechanism for Control I . Leyva, AFRL/RZ
J. Shepherd and H. Hornung, Cal Tech
CO2 Injection
From Hornung, H.G., Adam, P.H., Germain, P., Fujii, K., Rasheed, A., “On transition and transition control in hypervelocity flows,” Proceedings of the Ninth Asian Congress of Fluid Mechanics, 2002
CO2 Transition Re* is about 4X that of Air and N2
CO2
Air & N2
CO2
Air
Acoustic Absorption
2nd Mode Instability (Acoustic)
For CO2 internal energy and acoustic instability modes overlap
Curves for 3 total enthalpy values
24
Porous Injector Results (10 MJ/kg): CO2 Delays Transition Zero injectionTransition at
Re = 4.12 x 106
Ar injection at 11.6 g/sec Transition at
Re = 2.88 x 106
Exploring Transition Control Via Energy Transfer to Internal Modes
CO2 injection at 11.6 g/secLaminar Flow past
Re = 5.22 x 106
No
n-d
ime
ns
ion
al
He
at
Tra
ns
fer(
St)
Reynolds Number based on distance from nose tip
Turbulent Heating Correlations
Laminar Heating
Measured Heat TransferTransition Transition
Laminar
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Summary•Hypersonic flight requires advancement of critical scientific disciplines
• Agencies and countries are actively collaborating
• National Hypersonic Foundational Research Plan
• HIFiRE
• NATO RTO working groups
• High-fidelity, large-scale numerical simulations and laser-based diagnostics are changing the game
• Breakthrough science is impacting technology maturation
• Look for the exploitation of rate-dependent energetic processes
Thank You!